Overfill protection unit



FIG. 1 is a perspective view of a overfill protection unit showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a overfill protection unit, as shown and described. 